Why am I getting SQL State: 28000 FATAL: Ident authentication failed for user error message when running a simple Java program? – CentOS

I have a Postgres 11 database installed on a VirtualBox virtual machine running Centos7 (guest machine), and my host machine is a Mac OS Catalina. Both the guest (Centos) and host (Catalina) have JDK 8 installed.

I have the following simple Java code that uses a single dependency postgresql-42.2.5:

public class JavaApplication5 {

    public static void main(String[] args) {

        try (Connection conn = DriverManager.getConnection(
                "jdbc:postgresql://127.0.0.1:5332/mydb", "mydbuser", "mydbpassword")) {

            if (conn != null) {
                System.out.println("Connected to the database!");
            } else {
                System.out.println("Failed to make connection!");
            }

        } catch (SQLException e) {
            System.err.format("SQL State: %sn%s", e.getSQLState(), e.getMessage());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
}

I compile and run this on my host (Catalina) :

java -jar JavaApplication5.jar 

and the output I get is:

Connected to the database!

So clearly this means I can connect to the Postgres database from my host to my guest. Next, I test whether I can connect directly from my guest. So I copy "JavaApplication5.jar" into guest Virtual Machine running Centos 7 and re-run the same command. However, this time I am getting the following message from the same executable jar file:

SQL State: 28000
FATAL: Ident authentication failed for user "mydbuser"

Does anybody know why I am getting this error on the guest virtual machine but not on the host?

Here is the relevant portion of my my pg_hba.conf file:

# TYPE  DATABASE        USER            ADDRESS                 METHOD

# "local" is for Unix domain socket connections only
local   all             all                                     trust
# IPv4 local connections:
host    all             all             127.0.0.1/32            ident
# IPv6 local connections:
host    all             all             ::1/128                 ident
# Allow replication connections from localhost, by a user with the
# replication privilege.
local   replication     all                                     peer
host    replication     all             127.0.0.1/32            ident
host    replication     all             ::1/128                 ident
host all all 0.0.0.0/0 md5